What RCTs Do Not Show

Abstract

In this chapter we discuss how it is an uncontroversial norm of science that decisions should be based on evidence. There can be debate, however, on what counts as evidence and how we get from evidence to decision. The method of randomized controlled trials (RCTs) is now prominent in medical and social science. However, the method also has a number of weaknesses that are inherent to the design. There are some things that RCTs cannot test, while other interventions are well suited for the method. Among other consequences, it can be shown that the method structurally favours certain causal interventions over others.